1. Field of Invention
The present invention relates to interface circuit for signal transmission, suitable for use in wire communication system.
2. Description of Related Art
In applications of wire transmission, the conventional interface circuit for parallel signal receiver uses amplifying circuits to amplify the small amplitude of voltage signals into the amplitude in digital level. The parallel signal receiver needs one amplifier to amplify the clock signal and multiple amplifiers to amplify the data signals.
FIG. 1 is a circuit, schematically illustrating a conventional parallel interface circuit. In FIG. 1, the small signals to be transmitted include the clock signal clk and multiple input data signals, indicated by data 1, data 2, . . . , data n. The subsequent circuit after the interface circuit needs the signals with larger voltage amplitude. In conventional manner, each path for the small signals of clock signal and multiple data signals, data 1, data 2, . . . , data n needs to implement an amplifying circuit, 100_0, 100_1, . . . , 100_n, so as to amplify these small signals to the large output signals as the clock signal CLK and multiple data signals, indicated by DATA 1, DATA 2, . . . , DATA n.
In this conventional interface circuit, the total power and area consumption is depending on the number of data signals, in which each path of data signals is implemented with an amplifying circuit. The amplifying circuit in operation would have a static current, which causes further power consumption. In addition to the application of wire signal transmission, because the signals at the transmitting end has uncertainties, such as factors of amplitude size, signals quality, and level of common mode voltage, the performance of amplifying circuits at the receiving end need to adapt the wide range of the level of common mode voltage, high operation frequency, and gain. Thus, design of the amplifying circuit needs to have high gain, high operation frequency and high range of input voltage level. This design would also cause more power consumption.